Overview

The theory of planned behavior emphasizes that human behaviors are governed not only by personal attitudes, but also by social pressures and a sense of control. This model, when coupled with a few modifications, can generate some fascinating predictions. For example, individuals are more likely to execute rather than neglect their intentions, such as a plan to refrain from alcohol, if they express these plans on more than one occasion (Cooke & Sheeran, 2004).

Description of the model

The theory of planned behavior assumes that rational considerations govern the choices and behaviors of individuals (Ajzen, 1985; Ajzen, 1991; Ajzen & Fishbein, 2005). Specifically, according to a precursor of this theory, called the theory of reasoned action, behavior is determined by the intentions of individuals--their explicit plans or motivations to commit a specific act. For example, intention to quit smoking refers to an explicit commitment to this abstinence.

These intentions partly, but not entirely, reflect the personal attitudes of individuals, which is the extent to which they perceive this act as desirable or favorable. These attitudes reflect both cognitive beliefs about the act, such as whether they believe that smoking is harmful, as well as affective evaluations, such as whether they feel that smoking is unsuitable.

In addition, the degree to which significant individuals, such as relatives, friend, or colleagues, condone this act, called subjective norms, also affects intentions (Ajzen, 1985, 1991; Ajzen & Fishbein, 2005). The perceived importance or relevance of these relatives, friends, or colleagues affects the extent to which their approval will shape intentions. Furthermore, these weightings might vary across contexts. For example, the beliefs of relatives are likely to shape the intentions to engage in behaviors that relate to family life. In contrast, the beliefs of managers might be more likely to shape intention the intentions to engage in behaviors that relate to work life.

Finally, according to the theory of planned behavior, which represented a refinement to the theory of reasoned action, the extent to which individuals feel they can engage in these behaviors, called perceived behavioral control also impinges on their intentions and behaviors (Ajzen, 1991). Perceived behavioral control comprises two main facets. First, perceived behavioral control depends on the degree to which individuals conceptualize themselves as sufficiently knowledgeable, skillful, disciplined, and able to perform some act, called internal control (Kraft, Rise, Sutton, & Roysamb, 2005), which overlaps with the concept of self efficacy. Second, perceived behavioral control depends on the extent to which individuals feel that other factors, such as the cooperation of colleagues, resources, or time constraints, could inhibit or facilitate the behavior, called external control (Kraft, Rise, Sutton, & Roysamb, 2005).

Furthermore, intentions to perform some act do not always culminate in this behavior. Perceived behavioral control is partly, but not absolutely, related to actual behavioral control (Armitage & Conner, 2001), which in turn affects the extent to which intentions are associated with the corresponding behaviors. Perceived and actual behavioral control can sometimes diverge, such as when individuals are oblivious to factors that obstruct or facilitate the intented behavior.

Classes of social norms

Some researchers distinguish between different categories of social norms, which do not always translate into the same consequences. Schulz, Nolan, Cialdini, Goldstein, and Griskevicius (2007), for example, differentiate descriptive norms and injunctive norms. Descriptive norms are descriptions of the existing behavior of some collective or group. The proposition that "On average, households in this neighborhood consume 100 kilowatt hours per day" represents a descriptive norm. In contrast, injunctive norms are signals or depictions of the standards or preferences of some collective or group, representing which behaviors are approved and disapproved. A smiley face, for example, implies that a particular behavior is endorsed, imparting some information about the injunctive norms.

Descriptive norms and injunctive norms do not demonstrate the same effects. Specifically, when individuals are exposed to descriptive norms, they become more inclined to enact behavior that approximates this norm. If people are informed that households in the neighborhood consume 100 kilowatt hours per day, these individuals become more likely to utilize a similar level of energy in the future.

Accordingly, the dissemination of descriptive norms might sometimes improve, but occasionally compromise, the behavior of individuals. If they had previously consumed 150 kilowatt hours per day, these individuals might curb their consumption after they are informed that 100 kilowatt hours per day is average. If they had previously consumed 50 kilowatt hours per day, these individuals might increase their consumption after they are informed that 100 kilowatt hours per day is average.

However, injunctive norms might override this problem. If individuals are informed their behavior is desirable, they are inclined to enact this course of action more frequently in the future. Hence, even if told they exceed average, an injunctive norm, like a smiley face, might prevent complacency and foster even more desirable behavior.

Schulz, Nolan, Cialdini, Goldstein, and Griskevicius (2007) verified this account. In their study, some participants received only a descriptive norm about the energy consumption of houses in their neighborhood. Other participants also received an injunctive norm--they were exposed to a smiley face or sad face depending on whether their energy consumption exceeded the average.

If participants did not receive an injunction norm, after they were exposed to the descriptive norm, their energy consumption shifted towards this average. If their energy consumption had exceeded average, the descriptive norm increased conservation. If their energy consumption had been less than average, the descriptive norm undermined conservation. This problem, however, dissipated if a smiley or sad face had also been presented. Indeed these effects persisted over four weeks.

Furthermore, two classes of injunctive norms can be differentiated: societal and personal (Stavrova, Schlosser, & Fetchenhauer, 2011). Societal or social injunctive norms represent the opinions and attitudes of society towards some behavior. Personal injunctive norms represent personal opinions and attitudes towards some behavior.

In one context--unemployment--Stavrova, Schlosser, and Fetchenhauer (2011) showed that societal norms were especially likely to affect life satisfaction. That is, in 28 OECD nations, participants answered questions that assess personal injunctive norms towards unemployment benefits, such as "It is humiliating to receive money without working for it". The mean of these answers across each nation represented the societal injunctive norms towards unemployment benefits. Unemployment rate represented a proxy for descriptive norms.

Social injunctive norms were especially likely to be associated with life satisfaction: On average, if people in a nation perceive unemployment benefits as humiliating, the life satisfaction of unemployed individuals diminished. This relationship persisted after controlling other variables, such as unemployment benefits and demographic characteristics. Personal injunctive norms and descriptive injunctive norms were not appreciably associated with life satisfaction: The problems that unemployment induce, therefore, can primarily be ascribed to social stigma and not personal humiliation. Descriptive norms do not explicitly reflect societal attitudes and thus do not affect social stigma. Interestingly, generosity of the unemployment benefits did not affect life satisfaction.

Okun and Sloane (2002), for example, applied the theory of planned behavior to predict intention to volunteer and volunteer enrollment in a campus initiative. Attitudes to volunteering, social approval towards this act, and perceived behavioural control explained 62% of the variation in intentions. Perceived behavioral control--or the extent to whcih participants felt thatvolunteering is achievable, was the most pronounced determinant of intentions. Similarly, Giles and Cairns (1995) discovered that attitude, subjective norm, and perceived behavioral control explained 61% of the variance in intentions to donate blood.

Exercise

In many studies, only one or two rather than three of the cognitive determinants--attitudes, social norms, and perceived behavioral control--significantly relate to intentions (e.g., Ajzen, 1991). In one study, for example, Budden and Sagarin (2007) examined whether attitudes towards exercise (e.g., "Exercise in the next week is very pleasant"), subjective norms (e.g., "People who are important to me think I should exercise next week"), and perceived behavioral control (e.g., "I would like to exercise in the coming week but I don't really know if I can") were related to intentions to exercise (e.g., "I intend to exercise in the following week") and ultimately frequency of exercise over that week.

Attitudes to exercise and perceived behavior control were related to intentions to exercise. Subjective norms, however, did not uniquely contribute to these intentions. Finally, intentions were positively related to behavior.

The inclination of employees to voice their concerns

The theory of planned behaviour has been applied to predict the inclination of employees to voice their concerns about their organization and to offer solutions. Specifically, in a study conducted by Liang, Farh, and Farh (2012), participants completed measures that gauge the extent to which they voice their concerns about existing or imminent practices, called prohibitive voice, as well as the degree to which they suggest improvements, called promotive voice.

In addition, three proxy measures of attitudes, norms, and perceived control were included. To represent attitudes, participants specified the degree to which they felt safe to voice their opinions (e.g., "In my work unit, I can freely express my thoughts"). To represent social norms, participants indicated the extent to which they felt an obligation to express constructive opinions (e.g., "I have an obligation to the organization to voice out my own opinions). Finally, to represent perceived behavioral control, participants indicated their organizational based self-esteem (e.g., "I am trusted around here.")

Prohibitive voice was primarily dependent upon felt obligation, whereas prohibitive voice was primarily dependent upon psychological safety. Several interactions were observed as well. For example, psychological safety was especially likely to foster voice when felt obligation was high or when organizational based self-esteem was low. Psychological safety, therefore, is important if individuals feel compelled to voice some opinion but unconfident in their capacity to influence other people.

Faking behavior

The theory of planned behavior has also been utilized to predict the determinants of faking, such as lying or exaggerating, in job interviews. In one study, conducted by McFarland and Ryan (2006), applicants completed questions that assess their attitudes, norms, and perceived behavioral control in the context of faking. To assess attitudes, the questions revolved around whether faking is acceptable. To assess norms, the questions revolved around whether other friends or family would approve this faking. To assess perceived behavioral control, the questions revolved around whether the individuals could fake effectively. Finally, participants completed a personality test both honestly and in the context of a job application.

The average correlation between personality while answering honestly and personality while hypothetically applying for a job was .67. Some participants, therefore, distorted their responses while applying for a job. This distortion was especially pronounced in people who reported favorable attitudes and norms towards faking or experienced perceived behavioral control.

Some research has applied the theory of reasoned action or planned behavior to a work setting, such as support for an employee participation program (Dawkins & Frass, 2005), the use of structured interview techniques (van der Zee, Bakker, & Bakker, 2002), action plans of managers after performance feedback, (Maurer & Palmer, 1999), change management (Jimmieson, Peach, & White, 2008), and organisational misdemeanors (Vardi & Weitz, 2002).

Variance explained

Armitage and Conner (2001), in a meta analysis of 185 studied conducted before 1998, reported that attitueds, social norms, and perceived behavioral control explained 39% of the variance in intentions and 27% of the variance in behavior, across diverse domains. Social norms, however, was less related to intentions and behaviors than were attitudes and perceived behavioral control.

Accordingly, these components do not explain all the variance in intentions and behaviors. Other components or factors have been proposed. For example, in the domain of honesty, a measure of moral obligations was recommended as another potential determinant of intentions to act duplicitously (Beck & Ajzen, 1991; see also Conner, Smith, & McMillan, 2003).

To ascertain whether or not the various components explain intentions or behaviors adequately, some researchers argue that past behavior should also be included in the model (Beck & Ajzen, 1991). If past behavior is associated with future behavior, even after attitudes, social norms, and perceived behavioral control are included in the model, other components might need to be measured as well (see also Rhodes & Courneya, 2003). That is, this observation would indicate unexplained variance in behaviors could not merely be ascribed to random error, but to unmeasured systematic factors.

Indeed, the theory of planned behavior does not explain a broad variety of behaviors. For example, as East (2000) showed, the theory of planned behavior did not seem to predict the tendency to complain about products in a retail context.

Direction of causality

As some studies show, procedures that manipulate the components, such as change attitudes, do indeed affect intentions and behavior. These studies, thus, substantiate the hypothesized direction of causality.

Amjad and Wood (2009), for example, attempted to manipulate attitudes towards aggression against Jewish people. These researchers assessed whether or not a lecture is sufficient to change these attitudes and whether these changes influence the likelihood the individuals will join an extremist organization .

In one of their studies, half the students first listened to a presentation lasting 1 hour and 40 minutes, from a British Pakistani psychologist. The psychologist highlighted the history of victimization of Jewish people before the Crusades, the kind treatment of the Prophet Muhammad towards the Jewish people, the shared heritage of Muslims and Jews, as well as the sharing of knowledge between Muslim and Jewish scholars throughout history. This presentation elicited a lively debate. The remaining students received a lecture on cognitive behavior therapy, representing a control group.

Before and after the lecture, students answered questions that assess the extent to which they feel aggression towards members of the Jewish faith is appropriate. Specifically, they were asked to specify the degree to which they feel that cursing Jews in prayers, praying for God's wrath against Jewish people, damaging Jewish property, threatening Jewish people, speaking in public against Jewish people, writing negatively about Jewish people, and forwarding anti-Semitic e-mails or written material is right and appropriate. A few days later, a confederate, supposedly employed by the student union, approached the students in the class individually. The confederate asked these students whether they would like to join a Muslim youth force, formed to oppose enemies of their religion such as Jews. To disguise the purpose of this study, students were also asked whether or not they would like to join a book club.

The discussions about the close association between Muslim and Jewish people across history reduced the likelihood that individuals would accept aggression against Jewish people. In turn, as this endorsement of aggression diminished, individuals became less inclined to join the Muslim youth force.

Interactions between components

The theory of planned behavior assumes the components are additive: attitudes, social norms, and perceived behavioral control shape attitudes through distinct mechanisms rather than interact. However, social norms and perceived behavioral control--at least as manifested as resistance to temptation, did interact to affect dieting intentions (Bagozzi, Moore, & Leone, 2004). Specifically, social norms to diet were more likely to affect intentions when perceived behavioral control was elevated.

Methodological considerations

Typically, in most studies, between two and five questions are included to assess each component. Typical questions to assess social norms, for example, might be:

People who are important to me would want me (...describe act...)

People who are important to me would approve if I (...describe act...)

People who are important to me feel I should (...describe act...)

When researchers assess social norms, they ask participants to evaluate the extent to which significant individuals in their life would approve of this behavior. Sometimes, specific individuals are specified, such a "parents" or "best friend". On other occasions, more abstract phrases are utilized, such as "others". A recent "think aloud study" indicated that participants experience difficulties and ambiguities when global referents are used (French, Cooke, McLean, Williams, & Sutton, 2007).

Factors that moderate the associations between factors

The theory of planned behavior acknowledges that perhaps the relative importance of each component--of attitudes, social norms, and perceived behavioral control--can vary across individuals and contexts (Ajzen, 1991). For example, attitudes that are ambivalent (Conner, Povey, Sparks, James, & Sheperd, 2003) or demonstrate divergence between affective and cognitive facets are less likely to be related to behavior--although this principle might not apply to predictions of behavioral change (for a review, see Skar, Sniehotta, Araujo-Soares, & Molloy, 2008). Similarly, subjective norms might be more likely to affect intentions and behaviors in collectivism, rather than individualistic, cultures for example.

Disposition

Some personality or dispositional traits can also moderate some of the relationships that underpin the theory of planned behavior. Sheeran and Orbell (2000), for example, showed that intentions to exercise were more likely to relate to behavior when individuals perceived themselves as fit and healthy. In other words, intentions that correspond to the schemas or self perceptions of individuals are more likely to translate into behavior.

Cognitive deliberation

Sometimes, when people decide how they should behave, they deliberate carefully. On other occasions, they may be two distracted by other matters, or feel too rushed, to deliberate carefully. Deliberation has been shown to moderate the relationships between norms and intentions. Specifically, as Melnyk, van Herpen, Fischer, and van Trijp (2011) showed, deliberation amplified the relationship between descriptive norms and intentions but diminished the relationship between injunctive norms and intentions.

This study revolved around the intention to purchase potatoes that are environmentally suitable. To evoke descriptive norms, some participants read that residents of their nation prefer to purchase these potatoes. In contrast, to evoke injunctive norms, participants read two sentences about how people should purchase these potatoes. To curb deliberation, some participants needed to count the number of times the word "the" appeared while they read the information. To induce deliberation, some participants were asked to reflect upon their thoughts after reading the information.

When cognitive deliberation was encouraged, descriptive but not injunctive norms were more likely to be associated with both the intention to purchase these potatoes and the attitudes towards these potatoes. Conceivably, when granted an opportunity to deliberate, people may attempt to explain why other individuals conform to this descriptive norm, evoking positive thoughts about this behavior. Indeed, positive thoughts did mediate the relationship between descriptive norms and intentions. However, when granted an opportunity to deliberate, people may uncover arguments that counter the injunctive norm.

Mood

Armitage, Conner and Norman (1999) conducted a study that examined whether mood might affect the extent to which attitudes, social norms, and perceived behavioral control affects intentions. When participants experienced negative mood states, attitudes were more likely to be related to intentions than social norms. When participants experienced positive mood states, social norms, not attitudes, were more likely to be related to intentions.

According to Armitage, Conner and Norman (1999), negative moods tend to encourage individuals to process information more comprehensively and systematically rather than invoke heuristics or cues that are not rational. Explicit attitudes were touted as more rational than social norms and thus more closely related to intentions when mood was negative.

Stress also seems to moderate the relationship between intentions and behavior. One study, for example, showed that intentions to exercise were less likely to affect behavior in participants who experienced appreciable strain at work (Payne, Jones, & Harris, 2002).

Properties of the activities

The properties of tasks and activities can also moderate some of the relationships. The relationship between intentions and behavior, for example, diminishes when the tasks or activities are difficult (e.g., Bansal & Taylor, 2002). That is, when perceived behavioral control is low, and the tasks are difficult, intentions often do not translate into actions. That is, individuals might underestimate the importance of obstacles and constraints, and instead consider the benefits and merits, when they form an intention.

Demographics

Demographics also affect whether attitudes, social norms, or perceived behavioral control are most likely to affect intentions and behavior. For example, in a study conducted by Conner, Smith, and McMillan (2003), social norms to speed were more likely to affect the intentions of males, rather than females, to exceed the speed limit while driving alone.

Anticipatory socialization

Anticipatory socialization represents the practice of acquiring information and knowledge about some collective, group, organization, or role before individuals officially join or begin (see Levine & Hoffner, 2006; Shields, 2002). According to Stamper and Masterson (2003), immediately before individuals feel like a legitimate member of a group, they become more inclined to observe the norms, symbols, and rituals of this collective. Contractors, for example, who can be regarded as peripheral to the organizations, are often more sensitive to the social norms of an organization that permanent employees (see McDonald & Makin, 2000). Thus, the association between social norms and intentions or behavior might be amplified in participants who are yet to become established members of the collective.

These findings are consequential, and indeed encouraging, because contract workers are becoming increasingly prevalent in many organizations. Contractual arrangements include:

Seasonal workers, such as fruit picking

Temporary agency jobs, common in administrative roles

Fixed term work, such as consulting and trades

Jobs that tend to be casual, such as hospitality

Managers are increasingly motivated to offer these contractual arrangements to ensure the organization can respond rapidly and flexibly to the unpredictable changes in the environment. Second, contractual arrangements can curb some of the costs associated with permanent employees, such as annual leave, incentive schemes, and induction training; these arrangements also circumvent some legal responsibilities, in the realm of dismissal and insurance, for example. Third, organizations can assess the capabilities of potential permanent employees during these temporary periods. Finally, organizations can attract employees who enjoy or need the flexibility that such arrangements afford (for a review, see Burgess & Connell, 2006).

Antecedents of the cognitive components

The mental state of individuals can influence perceived behavioral control. Budden and Sagarin (2007), for example, showed that job strain can reduce perceived behavioral control. Individuals who reported they experienced many stressors at work, such as overtime, were more likely to endorse items like "I would like to exercise in the coming week but I don't really know if I can".

Sanctions and punishments

In many settings, people receive sanctions or punishments if they behave inappropriately. Individuals who do not disclose their financial details may be fined by the tax department, for example. In some instances, these sanctions might affect social norms and ultimately behavior. If tax fraud is punished, people might assume that society perceives such improprieties as immoral, for example.

However, according to Verboon and van Dijke (2011), these sanctions and punishments shape social norms in some instances only. Specifically, if the authorities are perceived as just, these sanctions and punishments influence norms or behavior. That is, when the procedures are fair, people feel these authorities represent a legitimate font of moral information. Their sanctions imply that a specific act, such as tax fraud, is really immoral.

In contrast, if the authorities are perceived as unjust, these sanctions and punishments do not influence norms or behavior. When the procedures are unfair, people feel these authorities are not a legitimate font of moral information. Individuals do not perceive the behaviors these authorities sanction as immoral. Instead, they feel these sanctions are intended for other reasons, such as to collect money.

To illustrate, in one study, conducted by Verboon and van Dijke (2011), participants indicated the extent to which they feel the tax office is fair--that is, the degree to which decisions are informed, unbiased, and receptive to feedback. The participants also specified the extent to which they comply with tax regulations. Finally, these individuals indicated whether they feel the fines that are dispensed when individuals do not comply with tax regulations are severe or lenient. If sanctions were perceived as severe, participants were indeed more likely to comply, but only if the tax office was perceived as fair.

Related theories

Goal framing theory

According to goal framing theory (Lindenberg & Steg, 2007), various cues in the environment determine whether or not norms govern behavior. According to this theory, individuals tend to pursue one of three sets of goals: hedonic goals, which are intended to enhance immediate pleasure, gain goals, which are intended to accumulate resources, and norms goals, which are intended to follow the social norms or conventions of the community. Some cues, such as graffiti, imply that norms are not usually followed. These cues, therefore, tend to activate hedonic goals or gain goals in lieu of norm goals.

This possibility was assessed by Keizer, Lindenberg, and Steg (2011). In particular, the researchers attached some brochures to bikes, located near a shopping mall. No bins were nearby. Therefore, when the owners returned to their bikes, they could either carry the brochures to another location or they could litter. The researchers manipulated whether or not the area was littered with some rubbish or covered with graffiti.

When the area was littered with neither rubbish nor graffiti, the erection of a sign that prohibits littering was actually effective: Participants were not as likely to litter. In contrast, when the area was either littered with rubbish or covered with graffiti, the erection of this sign actually increased the likelihood of littering. Presumably, because of this litter or graffiti, participants felt that social conventions tend to be violated. They felt, therefore, more compelled to diverge from the message this sign promoted.

References

Abraham, C., & Sheeran, P. (2003). Acting on intentions: The role of anticipated regret. British Journal of Social Psychology, 42, 495-511.

Blue, C. L. (1995). The predictive capacity of theory of reasoned action and the theory of planned behaviour in exercise research: An integrated literature review. Research in Nursing and Health, 18, 105-121.

Cooke, R., & Sheeran, P. (2004). Moderation of cognition-intention and cognition-behaviour relations: A meta-analysis of properties of variables from the theory of planned behaviour. British Journal of Social Psychology, 43, 159-186.

Fazio, R.H., & Williams, C. J. (1986). Attitude accessibility as a moderator of the attitude-perception and attitude-behavior relations: An investigation of the 1984 presidential election. Journal of Personality and Social Psychology, 51, 505-514.

Norman, P., & Smith, L. (1995). The theory of planned behaviour and exercise: An investigation into the role of prior behaviour, behavioural intentions and attitude variability. European Journal of Social Psychology, 25, 403-415.

Payne, N., Jones, F., & Harris, P. (2002). The impact of working life on health behavior: The effect of job strain on the cognitive predictors of exercise. Journal of Occupational Health Psychology, 7, 342-353.

Stavrova, O., Schlosser, T., & Fetchenhauer, D. (2011). Are the unemployed equally unhappy all around the world? The role of the social norms to work and welfare state provision in 28 OECD countries. Journal of Economic Psychology, 32, 159-171.